The objective of this multidisciplinary project is to establish a set of innovative, sensitive and practical tests of reproductive functions in men and women, and to demonstrate their application in the field of occupational safety and health. In men these tests will assess the physiological functions and fertility of spermatozoa, and will thus be able to detect very early testicular damage resulting from exposure to environmental hazards. The tests focus on sperm morphology in semen, sperm motility in semen and cervical mucus, and the ability of sperm to penetrate non-living, immature human oocytes and zona pellucida-free hamster eggs. This multiphasic approach to detection of early warning signs of reproductive toxicity is pioneering, and has never been applied in the field of occupational safety and health. In women the tests will detect occult pregnancy and predict whether spontaneous abortion is likely to occur. The tests focus on the changing levels of hCG in urine during the first two weeks of pregnancy, and their application to occupational medicine is also without precedent. The implementation of this project is in two basic phases. During the first two years, our expertise in human reproductive physiology will be applied to simplify the new tests and select the most sensitive and practical for application in the field. During the second two years, our resources in epidemiology and community medicine will be used to demonstrate application of the selected tests in several different populations of male and female workers exposed to different occupational health hazards.